Hypodermic syringe



May 29, 1923.

HASG? A. E. SMITH ET AL HYPODERMIC SYRINGE 2 Sheets-Sheet l Filed April'7, 1921 May 29, 1923. v l,4l56,7l7

' A. E. sMuTH ET As..

HYPODERMI C SYRINGE Filed April '7, 1921 2 Sheets-Sheet 2 Patented May29, 1923.

ET STAT EN? 'y retenir TEUR E. SMITH AND ARTHUR 1D. GRAY, 0F CHICAGO,ILLINOIS.

Application led April 7, 1921.

To all whom t may concern:

Be it known that we, ARTHUR E. SMITH and ARTHUR D. GRAY, citizens of theUnited States, and residents of Chicago, in the county of Cook and Stateof illinois, have invented a certain new and useful Improvement inHypodermic Syringes, of which the following is a full, clear, concise,and exact description, reference being hadk to the accompanyingdrawings, forming a part of this specification.

Our invention relates to hypodermlc s yringes especially adapted for useby dentists or physicians, and contemplates certain improvements inthose types of syringes which comprise glass barrels and preferablyglass plungers.

The embodiments of our invention herein illustrated are particularlycharacterized by certain fenestrated metal frames which house andprotect the barrels, and carry the finger pulls.

The frame in each case is so conformed and related to the glass barrelof the syringe that the strains to which the barrel is subjected in theoperation of the syringe are applied at such points and in such mannerthat danger of breakage of the barrel, or any part thereof, due to suchstrains, 1s eliminated. The frame or shell in each case comprises novelmeans for attaching it to the syringe barrel with which it isassociated, the attaching devices being designed to accurately centerthe barrel within the frame when the frame and barrel are assembled andfastened together. The inner diameter of the frame is preferably largerthan the outer diameter of the glass barrel, and the devices forattachin the frame and barrel are releasable. By vlrtue of thisarrangement, it is possible to sterilize the several parts in hot waterwithout danger of breakage of the several parts due to the differentcoreicients of expansion of the glass and metal. l

Other objects and advantages of our invention will appear as thefollowing detailed description progresses.

In the drawings illustrating` oui` invention Figure 1 is a sideelevation of a syringe embodying our invention;

Figure 2 is an axial sectional view of the device shown in Figure 1;'

Figure 3 is a section taken on line 3--3 of Figure 2;

Serial No. 459,354.

Figure 4 is an elevational view of a modified embodiment of ourinvention;

Figure 5 is an axial sectional view of the device shown in Figure 4; and

Figure 6 is a section taken on line 6-6 of Figure 5. l,

Similar characters of reference refer to similar parts throughout theseveral views.

Referring first to Figures 1 to '3, it will be noted that the syringecomprises a glass barrelilO, within which operatesv the hollow glassplunger 11, the inner cylindrical surface of the barrelL and the outercylindrical surface of the plunger being ground to fit, in accordancewith the usual practice. At its lower end the barrel is provided with anozzle 12, the outer surface of which is ground so that it may have aconical fluidtight fit with the needle cap 13. rlihe needle is indicatedat 14. The barrel shown in Figures 1 to 3 is provided with an upperHarige 15, 4and the shoulder at the lower end of the barrel is roundedas indicated at 16. As will hereinafter appear, we avail ourselves ofthe rounded shoulder 16 in securely, but releasably, attaching thefenestrated frame of our syringe to the syringe barrel. The barrel isfurthermore provided with volumetric scale markings as shown.

Those parts of the syringe thus far specifically described do not differparticularly from syringes of the glass barrel and plunger type now ingeneral use. 1t is the usual practice to provide a collar whichencircles the syringe barrel and lies against the under surface of theflange 15, the collar` being provided with lateral extensions whichserve as finger pulls. This arrangement affords the barrel no protectionwhatsoever against accidental breakage by dropping, etc., and

is furthermore unsatisfactory because upward pressure exerted upon thefinger pulls tends to break the flange 15 which, being of glass andnecessarily of limited cross section, is incapable of withstanding anyconsiderableforce directed against its under surface. Our inventionovercomes the shortcomings of the commonly employed arrangement justdescribed` and in addition affords other advantages not hithertoafforded by any of the syringes of the type to which our inventionrelates.

lVe prefer substantially to enclose the barrel of the syringe within ametal sheath, and with this object in view we rovide the metal frame 17,the frame being enestrated as inlli d-icated at 18 to reveal the scalemarkings on the syringe barrel. The inner diameter of the frame ispreferably somewhat larger than the outer diameter of the barrel so thatwhen the frame attachments are loosened as hereinafter described thebarrel will be free to expand and contract during and aftersterilization in hot water. It is moreover desirable to have the innerdiameter of the frame slightly larger than the outer diameter of thebarrel. because it is very difficultV to have the last mentioneddiameter absolutely uniform. The frame is provided at its lower end withan inclined annular lip 19, the inner surface of which bears against thebarrel shoulder 1G. The

lower end of the barrel is provided with a plurality of slits 20--20,and the several tongues afforded by the provision of these lips may beforced inwardly by an internally tapered milled nut 21, whichco-operates with the threads formed upon the tapered lower end of theframe. The frame is provided at its upper end with a tapered flange 22,which is adapted to co-operate with the reversely tapered internalthreads of cap 23., The upper end of the frame is provided witlfl aplurality of slits 24-24. It will be understood that when nut 23 isthreaded down upon the several sections of flange 22. the tonguesafforded by slits 24-24 will be forced inwardly against the uppercylindrical surface of the barrel. The cap carries the bar 25 which isfitted around the hollow boss 23, which projects upwardly from cap 23,and is turned over the bar. The bar, which affords the usual fingerpulls, may be either fixed or rotatable with respect to the cap, and ishere shown as being fixed to the cap by solder` indicated at 25a. 'YVhenthe bar is fixed to the cap. the ends of the bar serve as wings whichfacilitate threading the cap on and off' of the shoulder 22. In any casewhere the bar is made rotatable with respect to the cap the latter ispreferably eX- ternally milled.

Carried on the upper surface of the bar 25 is a wire spring 26 which issecured to the bar by any suitable means. as for instance by solderY2i'. and which has its legs conformed to hear frictionally against theglass plunger 11. The preferred conformation of the spring is the oneillustrated. this arrangement enabling each leg of the spring to engagethe plunger at. two lpoints. It is` of course` the function of thespring to retain the plunger in any adjusted position within the barrel.

Then the fenestrated frame and its several attachments are assembledupon the syringe. as illustrated in Figures 1 and 2, the several tonguesformed by the slits at the upper and lower ends of the frame are pressedfirmly into contact with the outer cylindrical surface of the glassbarrel, and

vthe lip 19 is pressed firmly against the rounded shoulder 1G. Since thesurface of the lip which engages the shoulder is conical, the lipautomatically properly centers the lower end of the barrel within theframe .when nut 2l is tightened upon shoulder 19.

When, in the normal operation of the syringe, pressure is exerted on thefinger pulls, this pressure is transmitted to the barrel through theframe. The friction tongues afforded by the slits in the frame tendevenly to distribute the exerted pressure over the barrel in suchfashion that any chance of the barrel breaking under such pressure isobfviated. In any case, where the mere friction of the tongues againstthe. cylindrical surface of' the, barrel is not sufficient to transmit,to the barrel the pressure exerted against the finger pulls. the lip 19transmits said pressure to the shoulder 1G which, being rounded. is to agreater extent than any other part of the barrel adapted to withstandthe force applied.

Whenever it is desired to sterilize the syringe in hot water. theplunger is removed and the nut 2l and cap 23 are loosened. and theentire device is immersed in the water. lVith the nut and cap thusloosened, and the plunger removed, neither breakage nor distortion ofparts will result` notwithstanding the fact that the glass and metalparts have different co-efiicients of expansion.

In Figures 4 to 6 we have illustrated a. modified embodiment of ourinvention, which is very effective and capable of being eco' nomicallymanufactured. ln describing this veliminated. the pressure of theslitted lower end of the frame against the glass barrel being sufficientproperly to hold the lower end of the barrel when the barrel shoulder isforced down against lip 19 in the manner presently to be explained. Theflange is eliminated from the upper end of the glass barrel in thismodification of our invention` the plain :upper end of the barrel lyingimmediately adjacent an annular conical surface 30 which is formed incap 23. The cap 23 and the upper end of the fenestrated frame areprovided with ordinary co-'operating serew threads. There are no slitsin the upper end of the frame of this -embodiment of our invention. Thebar 25 similarly to the corresponding bar of Figures 1 to 3 may eitherbe fixed to or rotatable with respect to the cap 23. When the cap 23 ofthe device number of parts and are somewhat cheaper to manufacture thanare the corresponding devices shown in Figures 1 to 3, hence for someclasses of work the arrangement illustrated in Figures 4 to .6 is apreferred embodirnent of our invention.

I-Iaving thus described our invention, what we claim is new and desireto secure by Letters Patent of the United States is:

1. In combination with a syringe comprising a glass barrel having arounded i shoulder at its lower end, a fenestrated frame fitting aroundthe barrel and provided at its lower end with an inturned lip having aconical surface arranged to bear against said shoulder, longitudinalslits in the lower end of the frame dividing said lip into'a pluralityof sections, and means carried by the frame for holding the severalsections of said lip tightly against the aforesaid rounded shoulder.

2. In combination with a syringe comprising aL glass barrel having arounded shoulder at its lower end, a fenestrated frame fitting aroundthe barrel having a conical portion arrangedvto bear against saidshoulder, a plurality of longitudinal slits in the lower end of theframe dividing said conical portion into a plurality of sections, andfinger pulls carried at the upper end of said frame.

3. In combination with a syringe comprisling a glass barrel having arounded shoulder at its lower end, a fenestrated frame tting around thebarrel having a conical portion arranged to bear against said shoulder,a plurality of' longitudinal slits in the lower end of the framedividing said conical portion into a plurality of sections, a capthreaded upon the upper end of said frame, and finger pulls carried bysaid cap.

4. In combination with a syringe comprising a glass barrel provided atitsllower end with a shoulder, a substantially cylindrical metal framefitting around said barrel and provided at its lower end with aninturned li arranged to bear against said shoulder, longitudinal slitsin the lower end of said frame dividing said lip into a plurality ofsections, a cap at the upper end of the frame arranged to preventdownward displacement of the frame, and linger pulls carried by saidcap.

5. In combination with a syringe of the class described, a cylindricalfenestrated metal frame provided at its lower end with an inturned lipproviding a conical surface arranged to engage at a region slightlyremoved from the cylindrical portion of said frame, a shoulder at thelower end of the barrel, and a cap carried at the upper end of theframe, the cap serving to prevent downward displacement of the frame,said inturned lip being slit so that it may yield when drawn tightlyagainst said shoulder.

6. In combination with a syringe including a glass barrel, a fenestratedframe fitting around said barrel, an inwardly tapering flange at one endof said frame, and slits in said flange dividing it into a plurality ofsections whereby said barrel is resiliently engaged.

7. In combination with a syringe includl ing a glass barrel, afenestrated frame fitting around said barrel, longitudinal slits in saidframe at the end thereof dividing the end of said frame into a pluralityof sections, and clamping means about said sections for causing them toengage said barrel at points removed from the portion of said sectionsengaged by said clamping means.

8. In combination with a syringe including a glass barrel, a fenestratedframe fitting around said barrel, longitudinal slits in said frame atthe end thereof dividin the end of said frame into a plurality osections, and screw threaded clamping means engaging the outer surfaceof said sections and causing portions of them not directly engaged bsaid clamping means to engage said barrel? In witness whereof, wehereunto subscribe our names as follows, April 4th, 1921.

Witnesses ALBIN C.v Animalia@ EMILE J. BOURGEOIS.

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